Thursday, May 31, 2012

Using Ivermectin For Demodectic Mange?

 by Simon Tong

Ivermectin is one of the few medicines that vets often prescribe for dogs with demodectic mange. The drug is easy to administer, and results are usually seen within a short period of time. It's been proven many times over that Ivermectin is successful in treating the skin problem, but that doesn't mean it can be considered as the de-facto solution for it.

Image: 2ndchance
The problem with Ivermectin is that it isn't the wonder drug that it appears to be. 

Yes, it does seem to get rid of the mange, but its only a temporary solution at best. And that's not to mention the various negative side-effects that can result from its use, some of which can even prove fatal.

How do you know if Ivermectin is the right type of treatment for your dog? 

Here are a few questions you should ask to help you decide.

What is Ivermectin?

Simply put, Ivermectin is an active ingredient in several medicines, specially designed for getting rid of parasites. In the pet world, these are available in several products meant for different animals, like horses and dogs.

For dogs, two of the most popular products are 'Ivomec' or 'Heartgard', both of which are marketed as parasite control drugs. They affect skin parasites and several others, such as heartworms. Ivermectin is also used to prevent heartworm infestations in dogs as well, although that's not its primary purpose.

How is it administered?

Ivermectin is usually produced in liquid or tablet form, which are administered to dogs orally - that is, the dogs are fed the drug. The dosage varies for each dog, determined by their weight. Usually the vet will provide the appropriate dosage, but generally speaking, a dose of 0.3mg/kg once every two weeks is sufficient for the treatment of demodectic mange. The liquid version of Ivermectin is sometimes packaged in filled syringes with set amounts, which makes it easier to gauge the dosage levels.

How does Ivermectin work?

Once it is administered to the affected dog, Ivermectin enters the bloodstream, using it as a means to affect the demodex mites in contact with the dog's skin. From that point onwards, the drug does two things: Firstly, it disables the nervous systems of the mites, effectively paralysing them. Then, it manipulates the dog's white blood cells into attacking the mites and killing them. In this way, the mites will no longer cause further skin damage to the dog's body. As long as the drug remains in the body, the demodectic mange will be kept away indefinitely.

Ivermectin doesn't affect unhatched demodex mites still in their eggs. Therefore, more than one dose of Ivermectin is required to completely eradicate the mites from the body.

Advantages of using Ivermectin for Demodectic Mange

Ivermectin has actually been proven to be capable of destroying the mites efficiently, which is why vets are still recommending it as their first choice in treating demodectic mange.

The drug is also very easy to administer, since they're designed to be ingested orally and not given in the form of injections. This removes any effort required to calm the dog, since an injection can be a stressful experience.

Lastly, Ivermectin is relatively safe when used responsibly. This requires the vet and the owner to fully understand the dog's condition and to adapt the treatment accordingly. If extensive care and caution is exercised, Ivermectin should not cause any trouble in the short-term.

Disadvantages of using Ivermectin for Demodectic Mange

So far, Ivermectin seems like the perfect method of demodectic mange treatment; it's safe, easy to use and most of all, it's effective. In spite of all this, however, there are still a few disadvantages of using Ivermectin that I would like to highlight.

It only solves half the problem

As I've said before, the purpose of Ivermectin is to kill off the mites that are causing demodectic mange to happen. However, that only settles part of the equation. The true key to stopping demodectic mange is to repair and rebuild your dog's immune system, because it's the only thing that can stop the demodex mites from appearing again. Even if all the mites are killed in one go (which is impossible, due to Ivermectin being unable to affect unhatched mites), the weak immune system will always be unable to prevent the mites from causing demodectic mange in future.

Reliance on Ivermectin

This is somewhat related to my first point. Some owners may discover by themselves that the drug is indeed a short-term solution; once the treatment stops for the affected dog, the mange might come back. Because the immune system wasn't strong enough to handle the mites on its own before the Ivermectin was withdrawn, it still remains vulnerable to another attack and may cause a relapse.

At this point, the owner can pursue two options: keep the Ivermectin flowing to shut the mites out permanently using chemical drugs, or start building up the immune system to help the dog to recover on its own. Unfortunately, some owners choose the first option and suddenly find themselves spending a lot more in pet medical bills, just to keep the problem from spreading.

Besides the increased expenses, depending on Ivermectin as a long-term solution can also cause the immune system to 'slack off', letting the drug do all the work. When the Ivermectin doses eventually cease (which it eventually will), the dog will be essentially defenceless against the mites because its immunity is non-existent. The demodectic mange will most definitely reappear with a vengeance then.

Possible adverse reactions to Ivermectin

This drug may be the default treatment recommended by vets to treat demodectic mange, but Ivermectin should never be given to some dogs due to possible adverse reactions.

Border collies and other herding breeds in particular have genetic sensitivity to Ivermectin; and a relatively low dose for another dog may be too much for a collie, and will cause severe side-effects such as lethargy, dehydration and even death.

Most people know about this genetic sensitivity and will keep their dog away from the drug, but it actually isn't as widely known as it should be.

Long term use in high doses may cause liver damage

This is another reason why Ivermectin should not be given for demodex over a long period of time. While relatively harmless when used as a temporary solution, or in low doses, at doses needed to treat demodectic mange the drug may cause damage to the liver in the long run. It's important to remember that Ivermectin is primarily a pesticide for use against parasites, which means that it's essentially a type of poison.


Ivermectin is often used to cure demodectic mange by killing the mites, and it does its job very well. The problem only starts when dog owners and even vets start treating it as a wonder drug due to a lack of understanding, and depend on it exclusively.

The one thing that you should know is that Ivermectin only solves the problem of a mite overpopulation on your dog's body as long as it's being administered; the mites will return as soon as it stops and will start the cycle all over again.

The mange will only clear up if the mites are denied the chance to spread, and the only thing that can do that is the immune system of the dog. 

Unfortunately, the Ivermectin does nothing to help in that regard. The only other way to control the mites would be through continuous use of Ivermectin, but as I noted earlier on in this article, it's definitely not an ideal treatment plan for your dog.

The dosage needed for treatment of demodectic mange is much higher than is used for heartworm prevention. Ivermectin has actually never been approved by FDA for use in such dosages. However, the off-label use of Ivermectin for demodectic mange is quite common.

Please take the above information into consideration before reaching for Ivermectin to treat your dog's demodectic mange.


Simon has a miniature schnauzer and owns a website devoted to gathering information about dog skin problems. Do you need more information about demodectic mange? Just visit to find out more about its causes, the demodex mite, as well as the various methods of treatment available.

Related articles:
Demodectic Mange: The 4 Most Important Questions You Should Ask 


  1. Ivermrctin is a very common medicine to dogs but better to consult a veterinary doctor before giving it to your dog.

  2. Great information guys, thanks for sharing :)

    Hope you're having a fun day :)

    Your pal Snoopy :)

  3. Thank you so much for sharing. Can ivermectin be used with tetracycline?

    1. I am not aware of ivermectin being contraindicated with tetracycline, but you should check with your vet; though I assume your vet is who prescribed both?

  4. How do I boost my dog's immune system? He is an 8 month old golden retriever and I just started him on Ivermectin today as his mange was getting worse instead of better. Thanks.

    1. Boosting the immune system is tricky and kind of a double-edged sword. It is best to work with a holistic or integrative vet.

      Of course, health starts with nutrition, so you might need to take another look at his diet. In general, immune system problems can develop from poor liver function, poor gut health, poor carbohydrate diet, mineral imbalances ...

    2. Liz - See with your vet if you can try Ester C immunity booster. I plan on giving it to my GSD. Good luck!

  5. what's considered long term use of this medicine? just started my pug on it yesterday-beginning with .1 and going up to .5 ml for 5 weeks. He has a little spot under his chin.

  6. oh. AND he had diarrhea all night...from .1 ml...not sure if I should worry.

    1. Every time any medication either isn't working or causing side effects, it is important to talk about these things to the prescribing vet.

  7. Please tell me what is the equivalent of 0.3/kg in ML for administering Ivermectin to my dog who has red mange. She needs to be treated badly. Please help by letting me know soon. The right amount in MLs. This is the veterinarian needed I have, in ML dosages. Thanks in advance so very much.